Blue-Green vs Medieval Forest

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Medieval Forest is a little darker, more muted, warmer than Blue-Green.

Can I use Medieval Forest instead of Blue-Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Medieval Forest is a little darker, more muted, warmer than Blue-Green.

Can I use Blue-Green instead of Medieval Forest?

The same difference applies the other way round: Blue-Green is a little lighter, more saturated, cooler.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.